Method of making castings.



NIT

WILLIAM A. ROLE, OF PITTSBURGIEI, PENNSYLVANIA.

METHOD OF MAKING CASTINGS.

Specification of Letters Patent.

Patented May 29, 19M;

No Drawing. Application filed September 25, 1912, Serial No. 722,218. Renewed April 12, 1917. Serial No.

To all whom it may concern.

Be it known that I, WILLIAM A. Born, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Methods of Making Castings, of which the following is a specification. o

This invention relates to improvements in the art or metal-casting.

' mg the mold with an inert gas before.

the metal is poured into the same, air with its contained oxygen is expelled and castings free from defects due to the ab sorption of oxygen can be produced. As the amount of inert gas necessary,-especially where large castings or ingots are made,-

must be large, the methods heretofore suggested or utilized, so far as I am aware, have been unsuccessful, principally due, I believe, to the cost of the gas employed.

My invention consists in employing for the purpose of filling the mold, which may either be a sand mold as'iri ordinary cases of iron or other metal-casting, or metal molds as employed in making ingots, gases whose cost is low, such ,as the exhaust gases from an internal combustion engine or flue gases which are the products of combustion. I have found by experience that either of these gases; that is, the exhaust gases from an in- 40 ternal combustion engine or flue. gases, are suficiently devoid of oxygen for this use, and that by using method ofpreventnig the defects in cast ngs or ingots due to the absorption of oxygen while the molten metal is in the mold, or

while entering the mold.

If desired, the exhaust ases frominternal due gases may be.

combustion engines or them I obtain a cheap 'tember, 1912.

scrubbed and "dried, or otherwise cleaned and stored for use, and then conveyed into the molds from which the atmospheric air isto be expelled and excluded, or the gases may be led directly from their source to the molds. The gases for filling the molds may either be led into the molds from the bottom or spilled into them from the top. 7

If desired, a retainer for the inert gas may be used which projects above the top of the mold so that the molten metal will be so I poured into the mold through an inert at-j mosphere and in fact the entire distance from the source of molten metal to the mold may be made to consist of inert gas when cheap gas, such as my invention contemplates, is used.

Having thus described my invention, what I claim is:

1. The method of preventing the absorption of oxygen by molten metal during operation of casting the metal, which conhole communicatlng with the upper end 0 the mold is maintained submerged by the inert gas, and then in pourin the metal to belcast into the mold throug the pouring ho e.

In testimony whereof, I have hereunto subscribed myname this 20th day of Sepso WILLIAM A. note.

Witnesses -WM. P. FLINT, Josnrrr CONNELLY. 

